The Syrian hamster is a suitable host for several infectious diseases. This laboratory is studing the inflammatory and immune response in various hamster infectious disease models which are ongoing in other investigators' laboratories. We are interested in any involvement (helpful or injurious) of acute phase reactants (female protein) and also wish to determine the isotype of antibody and correlatethese factors with the resultant immunopathology. In a persistent treponema model, hamsters have been found to become infected with syphilis and yaws and protective immune immunoglobulins have been isolated and identified. Two parasitic models also are being studied, 1) Leishmania produces a chronic disease in hamsters similar to human infection and an unusual deposit of amyloid in glomerulae of female hamsters, and 2) Plerocercoid infected hamsters also develop extensive amyloid, even in males which have incresed serum FP levels.